The hospitals, whose programs for emergency angioplasties without surgical backup were under review for the first time, had been seeking two-year extensions.

The six failed, for at least some of the time over the past two years, to meet some of the state standards for the program, including 24-hour operation and getting 80 percent of patients treated within two hours.

All six said they had taken steps to remedy the problems, such as recruiting additional staff.

A seventh hospital, Anne Arundel Medical Center in Annapolis, was found to have met all the standards and was granted a two-year extension.

The commission said it would monitor the hospitals during the year, and could take stronger action if the problems aren't fixed.

Dr. Rex W. Cowdry, the commission's executive director, said there was no indication that patients had been harmed. He said the only measure of patient outcomes - whether the blockage was successfully cleared - was over 90 percent for the group, considered a good rate.

Eventually, he said, the commission hopes to set up measures in such areas as mortality and infection rate.

For years, the state only allowed angioplasty in hospitals that had the capacity to do heart surgery as a backup in case complications developed. In 1996, a group of hospitals that don't do heart surgery were approved to do emergency angioplasty on an experimental basis for patients with a certain type of heart attack. Based on that study, they were allowed to continue.

The commission acted on Baltimore-area hospitals yesterday. At future meetings, it will consider extensions for other hospitals in the state, and applications for approval from hospitals which haven't done angioplasty in the past.